Believe it or not, it’s time for Bierkeller Columbia’s annual Oktoberfest. The brewpub will host the event for three full weekends this year, beginning this weekend. Now in its second year, Bierkeller’s Oktoberfest celebration marks the high point of the brewery’s festival season. This year will feature multiple bands, including old favorites such as The Channelheimers and newcomers such as Vince Demore and Polka Cola, as well as beer and food specials.